Processes for the removal of triclosan in the environment and engineered systems: A review

Triclosan (TCS) is a synthetic chlorinated aromatic compound and a typical antibacterial agent widely used in a diverse range of personal care products. Generally, after normal use, TCS is flushed into the sewage system through drainage. However, because of its incomplete removal in wastewater treatment plants, the remaining TCS enters the environmental surroundings via treated effluent as well as through sludge disposal. This not only increases TCS concentrations in the environment, but it can also lead to the bioaccumulation of detectable levels of TCS in food webs from aquatic organisms to humans. Experimental evidence has shown the potential negative effects of TCS and its metabolites to a range of marine and terrestrial organisms. This review systematically summarizes the current state of knowledge on occurrence, negative effects, and degradation mechanisms of TCS by abiotic and biotic processes. We finish by discussing research efforts aimed at identifying knowledge gaps between biochemistry and degradation pathways of TCS.